cocoa fudge cake

A substitute for the applesauce would be pureed prunes. (Chocolate is great
with prunes.) A year or so ago, we used to be able to buy stewed, pureed
prunes in the baking section of our grocery store but I haven't been able
to find it for some months. Does one just puree prunes in a blender?
Isn't that too much liquid? Does anyone have any suggestions? Thanks